netdev - Re: Fix NULL dereference in x25

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 1 Nov 2011 22:15:25 -0400
From:	Dave Jones <davej@...hat.com>
To:	Eric Dumazet <eric.dumazet@...il.com>
Cc:	netdev@...r.kernel.org, Matthew Daley <mattjd@...il.com>
Subject: Re: Fix NULL dereference in x25_recvmsg

On Wed, Nov 02, 2011 at 03:10:45AM +0100, Eric Dumazet wrote:
 > Le mardi 01 novembre 2011 à 21:53 -0400, Dave Jones a écrit :
 > > commit cb101ed2 in 3.0 introduced a bug in x25_recvmsg()
 > > When passed bogus junk from userspace, x25->neighbour can be NULL,
 > > as shown in this oops..
 > > 
 > 
 > Your patch seems fine but :
 > 
 > Are you sure this bug is not present on previous kernels ?
 > 
 > It seems we had prior to this commit :
 > 
 > skb_pull(skb, x25->neighbour->extended ?
 > 	X25_EXT_MIN_LEN : X25_STD_MIN_LEN);

It might have been possible with a specifically crafted set of arguments.

It never showed up in testing before now, probably because we were
returning from the function before we got to that skb_pull
via all the other tests that get performed.

	Dave


--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html